The trachea is the formal term for the windpipe. Tracheotomy (Greek -tomia, cutting), also tracheostomy (Greek stoma, mouth), is an incision in it to relieve an obstruction to breathing; tracheitis is inflammation of it. The eye disease trachoma derives from the same Greek root: the eyelashes turn inwards and roughen the surface of the eye, eventually leading to blindness if untreated.